Optical connectors are usually used for the connection of optical fibers to optical elements. These optical connectors consist of a first housing retaining an optical fiber and a second housing retaining an optical element. The optical fiber is usually retained by means of a ferrule surrounding the optical fiber, and the optical fiber surrounded by the ferrule is secured in the first housing by means of a so-called harness. Sometimes, the front end of the optical fiber can be damaged in the process of the handling of this harness which results in deterioration of the transmission characteristics and in an inaccurate transmission of the optical signals.
A method intended to prevent the front end of the optical fiber surrounded by a ferrule from damage is shown in Japanese Utility Model Disclosure Sho 63 (1988)-128511. According to this method, the ferrule is secured in the housing in such a manner that the front end of the optical fiber is recessed from the front end of the housing, and the connection of the front end of the optical fiber and the optical element is accomplished by means of a short optical fiber or other optical transmission medium. While this method makes it possible to prevent the front end of the optical fiber form damage during the handling of the harness, it produces additional surfaces of connection between the short optical fiber and the optical fiber secured by the harness and between the short optical fiber and the optical element, which results in an increase in the alternation of the optical signals transmitted through the connector.
Another method of solving this problem consists of providing a spring biased protective member enclosing the front end of the optical fiber and biased forward, farther than the front end of the optical fiber. When the optical fiber is mated to the optical element, the protective member is pushed back as shown in Japanese Patent Disclosure Hei 1(1989)-316711. In this method, the biasing spring is made rather strong so that it would be impossible to push the protective member back by a tool or some other item. However, such a design requires a high mating force to push the spring biased protective member back in order to expose the optical fiber ends. Another disadvantage of this method is that it requires additional parts.
The object of this invention is to offer an optical connector having relatively few parts and providing protection for the front end of the optical fiber.